通过闭合幅度成像检测射手座A*的内在尺寸
Geoffrey C Bower1, Heino Falcke, Robeson M Herrnstein
1Astronomy Department and Radio Astronomy Laboratory, University of California, Berkeley, CA 94720, USA. gbower@astro.berkeley.edu
概括
研究人员测量了射手座A*的大小,这是我们银河系中心的超大质量黑洞. 这种无线电辐射起源于非常接近黑洞事件地平线,为其属性提供了新的见解.
科学领域:
- 天体物理学 天体物理学
- 无线电天文学 无线电天文学
背景情况:
- 射手座A*是位于银河系中心的超大质量黑洞.
- 了解超大质量黑洞的直接环境对于测试广义相对论和积累理论至关重要.
研究的目的:
- 为了确定射手座A*在毫米波长的内在尺寸.
- 探测位于射手座A*事件地平线附近的区域.
主要方法:
- 利用非常长基线阵列 (VLBA) 进行高分辨率无线电观测.
- 在7毫米波长进行观测.
主要成果:
- 射手座A*的内在尺寸被测量为24 +/- 2施瓦茨柴尔德半径,波长为7毫米.
- 在一个观测时期检测到内在源大小的显著增加 (60(-17)(+25)%).
- 确定了射手座A*的质量密度的下限,即每立方天文单位1.4×10^4太阳质量.
结论:
- 来自射手座A*的短波无线电辐射源自接近事件视界的近距离.
- 观察到的尺寸变化可能为黑洞附近的积累过程提供线索.
- 这些发现限制了黑洞物理和环境的模型.
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